John 3:4
Nicodemus said unto him, How can a man be born when he is old? can he enter the second time into his mother's womb, and be born?
John 3:3
Jesus answered and said unto him, Verily, verily, I say unto you, Except a man be born again, he cannot see the kingdom of God.
John 4:11-12
The woman said unto him, Sir, you have nothing to draw with, and the well is deep: from where then have you that living water?
John 6:53
Then Jesus said unto them, Verily, verily, I say unto you, Except you eat the flesh of the Son of man, and drink his blood, you have no life in you.
John 6:60
Many therefore of his disciples, when they had heard this, said, This is a hard saying; who can hear it?
1 Corinthians 1:18
For the preaching of the cross is to them that perish foolishness; but unto us who are saved it is the power of God.
1 Corinthians 2:14
But the natural man receives not the things of the Spirit of God: for they are foolishness unto him: neither can he know them, because they are spiritually discerned.